docs: def add_line_to_file(self, line, filename, expect=None, shutit_pexpect_child=None, match_regexp=None, loglevel=logging.DEBUG):
  		"""Deprecated.
  
  		Use replace/insert_text instead.
  
  		Adds line to file if it doesn't exist (unless Force is set, which it is not by default).
  		Creates the file if it doesn't exist.
  		Must be exactly the line passed in to match.
  		Returns True if line(s) added OK, False if not.
  		If you have a lot of non-unique lines to add, it's a good idea to have a sentinel value to add first, and then if that returns true, force the remainder.
  
  		@param line:          Line to add. If a list, processed per-item, and match_regexp ignored.
  		@param filename:      Filename to add it to.
  		@param expect:        See send()
  		@param shutit_pexpect_child:         See send()
  		@param match_regexp:  If supplied, a regexp to look for in the file instead of the line itself, handy if the line has awkward characters in it.
  
  		@type line:           string
  		@type filename:       string
  		@type match_regexp:   string
  
  		"""
  		shutit_global.shutit_global_object.yield_to_draw()
  		if isinstance(line, str):
  			lines = [line]
  		elif isinstance(line, list):
  			lines = line
  			match_regexp = None
  		fail = False
  		for fline in lines:
  			if match_regexp is None:
  				this_match_regexp = fline
  			else:
  				this_match_regexp = match_regexp
  			if not self.replace_text(fline,
  			                         filename,
  			                         pattern=this_match_regexp,
  			                         shutit_pexpect_child=shutit_pexpect_child,
  			                         expect=expect,
  			                         loglevel=loglevel):
  				fail = True
  		if fail:
  			return False
  		return True